Olympic champion Sammy Wanjiru of Kenya set a course record of two hours five minutes 10 seconds in the men's London marathon on Sunday after breaking away from the lead group 29 km into the 42.195-km race.
Wanjiru, second last year behind compatriot and former course record holder Martin Lel who withdrew on Saturday because of a hip strain, was prominent in the leading group which set a scorching pace through the first half.
The top group flew through the halfway stage in 61 minutes 35 seconds, the fastest ever split in a marathon.
But inevitably the pace slowed markedly, allowing time for Wanjiru to gather his strength and take the lead in a front trio which included the other two Beijing medallists Jaouad Gharib of Morocco and Ethiopian Tsegaye Kebede.
Wanjiru was forced to work hard in the final kilometres, glancing anxiously over his shoulder, as Kebede narrowed the margin. He surged again with two km to run and held on to win ahead of Beijing bronze medallist Kebede, who clocked 2:05:20. Twice world champion Gharib was third in 2:05:27.
Eritrean Zersenay Tadese, whose marathon debut had been eagerly awaited after a distinguished track and cross country career, dropped out at the 35 km mark.
Mikitenko retains women's title
German Irina Mikitenko retained the women's marathon title after taking the lead at 32 km and striding to victory in two hours 22 minutes 11 seconds.
Mikitenko ran shoulder-to-shoulder with Briton Mara Yamauchi after Chinese Olympic bronze medallist Zhou Chunxiu fell off the pace after 27 km of the 42.195 km race.
She stepped up the tempo through Canary Wharf and moved steadily ahead of the Briton to record her third win in only four marathons after a long track career.
Yamauchi was second in 2:23:12 and Russian Liliya Shobukhova third in 2:24:24.
Olympic champion Constantina Dita dropped off the pace early in the race, trailing the leading group by nine seconds after five km. She pulled out of the race at the halfway stage complaining of breathing difficulties.
After 10 km, the front group had already shrunk to Mikitenko, Zhou, Yamauchi and Japanese Mika Okunaga.
Okunaga was the next to fade before the field passed the halfway stage in 1:10:53, a minute ahead of the second group which included twice world champion Catherine Ndereba.
Zhou found the pace too fierce after 27 km and the race came down to the German and the Briton who ran side by side on the road leading to Canary Wharf.
Mikitenko then stepped up the pace and established a clear lead over Yamauchi.
Yamauchi, sixth in last year's Beijing Olympics, held on for second place to compensate the large crowd for the absence of British world record holder Paula Radcliffe who pulled out of the race because of a broken toe.